BOOMER! As you may know, that saying is uttered a lot in the hit Valve game, Left 4 Dead 2. This achievement tutorial focuses on the DLC, The Passing, and requires that you use two controllers to get this achievement. It can be difficult to get, but is totally worth it in the end. So check out the video above for more information on how to get the Wedding Crasher achievement. Good luck and watch out for those zombies!